Are there debuggers out there that would allow a user to query the value
of a #defined constant ? I am aware that HP compilers support an option
in which macro values are preserved in a special table in the objects
files. This could then be used to answer queries.

How about other debuggers ? If they do support this, it would be
interesting to know what techniques are used for this purpose. Also I am
interested in hearing how valuable folks think this capability is.